There are still no reliable data for Europe on the proportion of the population with the disease (so-called prevalence) and on the number of new cases (so-called incidence).

A population based study from the USA that recorded data between 1988 and 1990 is currently the only reliable study on the incidence of fibrosing lung diseases. According to this study, the total number of patients is 67.2 (females) and 80.9 (males) per 100,000 inhabitants and the number of new cases of the disease per annum is 26.1 (females) and 31.5 (males) per 100,000 inhabitants.

Based on these figures, it is clear that fibrosing lung diseases occur much more frequently than has so far been assumed. Extrapolating to Europe, we estimate that approximately 750,000 patients have lung fibrosis.